just glanced at your backlink profile... you've lost something like 10,000 links over the last week or so. if those were all poison links, that's fantastic for you!
NOW you need to start building quality links or you'll never regain your rankings.
so get out there and do some link building. That's my best advice to you. apart from a redesign and better optimized content.
img alt tags are a problem as Dennis suggested. a quick peek shows one alt tag that says "search" and another that reads "McAfee SECURE sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams"
These are both perfectly wrong examples and should be fixed.
Also, clean up that HTML it's gonna be difficult to manage in such a cluster like that. (my own personal gripe.. you may work differently than I)